That´s of course true, but for 500 mm zoom even a short exposure can be long enough to need a tripod, especially in shady conditions like forest or cloudy weather. Unless you have a very fast lense, that is, but for compact superzooms this is hardly the case.

Of course if you are shooting a moving object, tripod is of no use.

As to the Auto mode giving always best results, it´s quite childish to think so - what on earth would manual mode be needed if it were so! The main problem with auto mode is increasing ISO.